Insulating means



AUSL 2, 1966 c. A. STICKEL" 3,264,165

INSULATING MEANS Filed NOV. 25, 1964 U. Ar 'fl -4- .an .I .-7 .YAY -lr4 1. ORGANIC RESIN GLASS FIBERS AND INSULATING GAS METAL FILM PO LYVINYL ALCOHOL POLYUR ETHANE FOAM CONTAINING INSULATING GAS METAL FL"l POLYETH YL EN E.

United States Patent O 3,264,165 INSULATING MEANS Carl A. Stckel,Dayton, Ohio, assigner to General Motors Corporation, Detroit, Mich., acorporation of Delaware Filed Nov. 25, 1964, Ser. No. 413,852 8 Claims.(Cl. 161-43) This application is a continuation-in-part of my copendingapplication SLN. 160,009 filed December 18, 1961 now Patent No.3,206,345.

This Iinvention relates to improved insulating means. It has beenrecognized that certain gases with inherently low coefficients of heattransmission after displacing air from insulating materials willsubstantially increase the insulating properties of good insulatingmaterial such as glass fibers or mineral wool. However, it has beendifiicult to provide for permanently enclosing such gases in the glassfibers or mineral wool. It has also been difficult to prevent theleakage of such gases and to prevent the puncturing of the enclosureduring the handling of it afterward. Various means have often beenproposed for accommodating the expansion and contraction of the gasduring extreme changes lin temperature and also in barometric pressure.

It is an object of my invention to provide a permanently sealedresilient insulation containing a gas having a low coefiicient of heattransmission.

It is another object of my invention to provide a simple improved meanshaving high insulating value for protecting the enclosure of the sealedresilient insulation from puncture and leakage during processing andsubsequent handling and also to accommodate the expansion andcontraction of the gas sealed therein.

These and other objects are attained in the first form shown in thedrawings in which a piece of glass fiber or mineral wool is provided onits opposite faces with the protective strips of open cell foam orpaper. This assembly is enclosed in a thermoplastic film formed ofsheets :located on the opposite faces of the protection strips 'with theprotruding edges heat sea-led together to complete the enclosure. Theentire interior of the thermoplastic film enclosure containing theprotective strips and the piece of glass fibers or mineral wool `isprovided with a gas having a low coefficient of heat transmission whichis substantially permanently contained therein. To seal and protect thefilm and to provide a resilient outer layer, the entire outer surface ofthe film is provided with a thick coating of a closed cell substantiallyimpervious resilient foamed polymer preferably also substantiallypermanently containing a gas having a low coefiicien-t of heattransmission.

In the second form of the invention the interior is similar, but thethermoplastic film is provided with a vapor deposited film of a suitablemetal such as aluminum. The closed cell substantially imperviousresilient foamed polymer containing a gas having a low coefficient ofheat transmission is provided in a thick coating over the thin metalfilm. A sealing coating of organic resin is applied over the foamedpolymer and a second metal film similar to the first may be applied overthe sealing coating. Over the second metal film is a second sealingcoating of a suitable organic resin such as polyethylene. The interiorof the second form contains glass fibers or mineral wool and aprotective strip on opposite sides of the glass fiber or mineral wooland also contains a gas having a low coefficient of heat transmission.The metal films as well as the sealing coatings for the foam polymersubstantially prevent the escape of any of the insulating gas for anextremely long period.

Further objects and advantages of the present invention will be apparentfrom the following description, reference being had to the accompanyingdrawings wherein pre- ICC ferred embodiments of the present inventionare clearly shown.

In the drawings:

FIGURE 1 `is a diagrammatic `transverse sectional View of the first formof insulating means embodying my invention;

FIGURE 2 is a diagrammatic transverse sectional view of the second formof insulating means embodying lmy invention.

FIGURE 1 shows an insulation package in which there is a piece 34 in theform of a rectangular slab of glass fibers or mineral wool. Some glassfibers and mineral wool contain sharp needle-like pieces which maypuncture the enclosing -thermoplastic film or sheet. To avoid thispossibility of puncturing provided such materials are used, I provide onopposite sides of the glass fiber or mineral wool 34 upper and lowersheets 60 and 56 of thin open -cell foam elastomeric sheeting or craftpaper of substantially the same width as the glass fibers or mineralwool piece 34. The assembly of the glass fiber or mineral wool piece 34and the protective sheets 56 and 60 is enclosed on opposite sides bysheets 50 and 62 of heat sealable thermoplastic film or sheet which areheat sealed together at all their edges 61 to complete the enclosure.Examples of such film or sheet are one or more layers of vinylidenechloride sheet or a copolymer of vinyl chloride and vinyl chlorideacetate or a copolymer of vinyl chloride and vinylidene chloride or apolyester of ethylene glycol and terephthalic acid. The air within theenclosure provided by the sheets 50 and 62 is preferably replaced by agas having a low coefficient of heat transmission such asdifiuorodichloromethane or sulphur dioxide.

According to my invention, this film is protected by a thick outercoating 177 of a flexible resilient closed cell substantially imperviousfoamed polymer directly adherent to the film. This foamed polymercontains in its cells a gas having a low coefficient of heattransmission. Preferably the foam polymer 177 is of the polyurethanetype and contains as the insulating gas monofiuorotrichloromethane.

As one example of materials forming a flexible closed cell substantiallyimpervious foam polymer, such as the foam polymer 177, there is suppliedfor one component f' A in parts by weight a mixture of 44 parts oftoluene diisocyanate and l5 parts of monofiuorotrichloromethane. Thetoluene diisocyanate consists of a mixture of parts 2,4 toluenediisocyanate and 2O parts of 2,6 toluene diisocyanate. For the secondresin component B, lthere is provided a mixture in parts by weight of9() parts castor oil, l0 parts of distilled tall oil and 3 partscatalysts including one half part of N-ethyl morpholene, .2 partstannous octoate, 1.0 part of tetramethylguanidine. The resin componentB also includes a surfactant in the amount of 1.5 parts oforganosiloxane. These components are mixed and sprayed onto the entireouter surface of the films 50 and 62 in sufficient thickness to provide.a thick protective coating of the films sufiicient to protect the filmfrom puncturing, tearing and abrasion during handling and installation.

It should be understood that it is especially important to protect thefilm 5t), 62 from being punctured by external means since the loss ofthe insulating gas, difiuorodichloromethane or sulphur dioxide, from theinterior greatly reduces the insulating properties of the package. Thefoam 177 protects the film 50, 62 from being punctured by external meansand in addition seals the film to further prevent the escape of the gastherein having the low coefficient of heat transmission and alsoprevents the ingress of air thereto. It makes it possible for thepackage to withstand the normal abuses imposed during handling which wasa problem with film enclosed insulation.

The cellular structure of the foam is especially effective in sealingany minute holes which may be present in the film. The cellularstructure of the foam also makes it effective in preventing cutting andpenetration by sharp objects. The cellular structure of the foam and thepresence of the insulating gas in the foam have sufficient insulatingproperties to minimize the effect of external temperature changes on thegas in the interior of the film and thereby minimizes consequent changesof the pressure of the gas therein. The resiliency of the cellularstructure makes it possible to expand and contract to fill voids in theinsulation space and to absorb increases in pressure of the gas duringcontraction and expansion of the insulation gas within to ll any voidsin the insulation space within which the package may be lodged.

The second form of the invention embodies an insulation package shown inFIGURE 2 in which there is a fiat rectangular piece of glass fibers ormineral wool 134. As in FIGURE 1, this piece 134 is covered on its upperand lower faces by a lower protector sheet 156 and an upper protectorsheet 160 of open cell elastomeric foam or kraft paper. These protectorsheets prevent the possibility that some sharp needle-like piece withinthe glass fibers or mineral wool 134 will puncture the enclosing film.As in FIGURE l, the assembly of the piece of glass fibers or mineralwool 134 and the protector sheets 156 and 160 is enclosed by lower andupper sheets 150 and 162 of a thin thermoplastic film. This film ispreferably made up of one or more layers of vinylidene chloride sheet rother heat sealable films or sheets such as vinyl chloride-acetatecopolymer or a copolymer of vinyl chloride and vinylidene chloride or apolyester of ethylene glycol and terephthalic acid. The latter sheetmaterial is preferred and preferably is provided with a thin vapordeposited coa-ting 163 of aluminum over its entire surface. However,prior to this deposition of the metal film the interior of the enclosureis evacuated and charged with a gas having a low coefficient of heattransmission such as difiuorodichloromethane or sulphur dioxide. Theedges 161 are also heat sealed together completely around the assemblyof the piece 134 and the protector sheets 156 and 160 before the vapordeposited metal film is applied.

The vapor deposited metal film substantially improves the holding of theinsulating gas within the interior and therefore prolongs theeffectiveness of the insulation. Where the useful life of the structurein which the insulation package is to be used is relatively short, themetal coating 163 may be omitted.

According to my invention to protect the enclosure from puncturing andtearing and to seal the thermoplastic film and to hold and protect themetal film, I apply a thick coating 176 of a resilient elastic flexibleclosed cell substantially impervious foamed polymer of the polyurethanetype, preferably containing in the cells thereof a gas such asmonouorotrichloromethane having a low coefficient of heat transmission.The specific example may be the same as that set forth for the coatingor layer 177 in FIGURE 1 and performs the same functions.

While this foam polymer is capable of retaining the gas in its cells fora long period of time, there is a tendency for its effectiveness to bereduced gradually by penetration by moisture vapor and air. To prolongthe insulation properties of the foam polymer, I provide the foampolymer 176 with a thin flexible external coating 178 of polyvinylalcohol or a polyester of ethylene glycol and terephthalic acid. Toprovide additional gas sealing properties I provide a second vapordeposited very thin flexible film 180 of aluminum to the externalsurface of the plastic resin 178. This film 180 may be omitted wheresome loss of insulating efficiency after a long time is not important.To protect the metal film 180 from puncturing and abrasion, and toprotect the polyvinyl alcohol coating from contact with moisture, Iprovide an outer coa-ting 182 of either polyethylene or a polyester ofethylene glycol and terephthalic acid. These outer coatings and filmsare sufficiently thin and flexible that they do not substantiallyinterfere with the iiexibility and resiliency of the much thickercellular layer 17 6 which is composed -of the foam polymer.

The external coatings provided make practical this gas lled type ofinsulation since it is possible for the insulation package to be readilyhandled without substantial danger of cutting or puncturing the sealingenclosure so that the escape of the gas is permanently prevented. Theresiliency and toughness of the coatings 178 and 182 on the outside ofthe foam polymer 176 add to the effectiveness in preventing cutting andpuncturing and also abrasion. The package may be made inexpensivelythrough the use of automatic machinery as illustra-ted in my copendingapplication S.N. 160,009 filed December 18, 1961. The package may beapplied to the interior of the hollow walls of refrigerators or otherinsulating structures such as insulated trucks and refrigerator cars.The foam layer can be compressed during periods of high pressure of thegas within the in-terior of the package to prevent excessive pressurestherein and it may expand during periods of low pressure resulting fromcold temperatures to ll any voids in the insulation space, Thus theinsulation package by the provision of this resilient foam layer iscapable of application to wider changes in temperature than packagesenclosed solely in solid films.

While the embodiments of the present invention as herein disclosedconstitute preferred forms, it is to be understood that other formsmight be adopted.

What is claimed is as follows:

1. Insulation comprising a resilient permeable insulating materialcontaining a gas having god insulating properties, a sealed bag of thinflexible material enclosing said insulating material and sealing saidgas in the insulating material, and a resilient foam material bonded t0the entire outer surfaces of said bag and completely enclosing the outersurfaces of said bag.

2. Insulation comprising a resilient permeable insulating materialcontaining a gas having good insulating properties, a sealed bag 0f thinflexible material enclosing said insulating material and sealing saidgas in the insulating material, and a resilient foam material bonded toand completely enclosing the outer surfaces of said bag, said foammaterial containing a preponderance of closed cells containing a gashaving good insulating properties.

3. Insulation comprising a resilient permeable insulating material inthe form of a relatively thick sheet of extensive area containing a gashaving good insulating properies, protector sheeting provided uponopposite sides of said resilient insulating material, a sealed bag ofthin flexible material enclosing said insulating material and saidprotector sheeting land sealing said gas in the insulating material, anda foam material bonded to the entire outer surfaces of said bag.

4. Insulation comprising a resilient permeable insulating materialcontaining a gas having good insulating properties, a 'sealed bag ofthin flexible material enclosing said insulating material and sealingsaid gas in the insulating material, and a polyurethane foam materialbonded to and surrounding and completely enclosing and protecting theentire outer surfaces of said sealed bag.

5. Insulation as specified in claim 4 in which the polyurethane foammaterial is substantially impervious and has a preponderance of closedcells containing an insulating gas.

6. Insulation as specified in claim 4 in which the polyurethane foammaterial has an external sealing coating.

7. Insulation as specified in claim 4 in which the polyurethane foammaterial has an external sealing coating having a layer of organic resinon opposite sides of a metal film.

E e 6 8. Insulation comprising a thick rectangular resilient ReferencesCited by the Examiner permeable insulation material containing a gashaving good insulating properties, a sealed bag of insulating ma- UNITEDSTATES PATENTS teria] enclosing and extending throughout both sides2,742,385 4/ 1956 Bovenkerk 161-407 and all the edges of said insulatingmaterial and sealing 5 2,817,124 12/ 1957 Dybvig 52-406 the gas in theinsulating material, and a foam material 2,869,336 1/1959 Smidl 52 404extending continuously over and completely enclosing the outer surfacesof said bag and being bonded continuously RICHARD W COOKE, JR PrimaryExamle,.

to the entire outer surfaces of both sides and all the edges o'f saidbag, 10 JOHN E. MURTAGH, Assistant Examiner.

1. INSULATION COMPSIRING A RESILIENT PERMEABLE INSULATING MATERIALCONTAINING A GAS GOD INSULATING PROPERTIES, A SEALED BAG OF THINFLEXIBLE MATERIAL ENCLOSING SAID INSULATING MATERIAL AND SEALING SAIDGAS IN THE INSULATING MATERIAL, AND A RESILIENT FOAM MATERIAL BONDED TOTHE ENTIRE OUTER SURFACES OF SAID BAG AND COMPLETELY ENCLOSING THE OUTERSURFACES OF SAID BAG.